Posturography measures and efficacy of different physical treatments in somatic tinnitus

Somatic modulation in tinnitus has been demonstrated by several studies although few investigations have been published on the efficacy of physical treatments in tinnitus subjects. In the present study the prevalence of somatic components to tinnitus were evaluated and the efficacy of two different physical treatments were compared: InterX® transcutaneous dynamic electrical stimulation and manual osteopathic therapy. Furthermore, posturographic measurements were analysed to verify the postural control in tinnitus subjects. 40 consecutive tinnitus patients, aged 18-65, were randomly selected for treatment (once a week for 2 months): 20 tinnitus subjects were treated with osteopathic manipulations, 20 with InterX®. They were evaluated pre and post therapy with audiogram up to 16 kHz, tinnitus pitch and loudness match, MML, THI questionnaire, posturography, structured interview with special attention on postural and movement influence on tinnitus, physical evaluation and osteopathic evaluation. 40 controls with no tinnitus, underwent audiological tests, postural and osteopathic evaluation for comparison. In our population, tinnitus sufferers presented more frequently musculoscheletal strains assessed with osteopathic visit and postural problems assessed with posturography measures in comparison with controls. Posturographic test, showed an average oscillating areas significantly greater in tinnitus participants (p ≤ 0.05), compared with control subjects. On the average in the treated groups, the enveloped areas were not significantly affected by either of the treatments. Tinnitus improved subjectively in most patients: loudness decreased, % time of awareness, % time of annoyance and quality of life was overall perceived as improved. This was mostly evident in subjects with muscular strain and tensions. This study indicates the benefit of physical, manipulation therapy for those patients with somatic modulation of their tinnitus, further studies are needed to establish the diagnostic or prognostic role of posturographic measurements.

Ultrasound-guided placement of a permanent percutaneous femoral nerve stimulator leads for the treatment of intractable femoral neuropathy

BACKGROUND

Femoral nerve injury is a rare complication of cardiac catheterization and is usually caused by direct trauma during femoral artery access, compression from a hematoma, or prolonged digital pressure for post-procedural hemostasis. Peripheral nerve stimulation has been used to treat different pain syndromes in the upper and lower extremities with variable success and it typically requires direct vision with open surgical approach. Since the femoral nerve can be readily seen with ultrasonography, an ultrasound-guided lead placement seemed practical.

CASE REPORT

A 61-year-old morbidly obese male who sustained femoral nerve injury during cardiac catheterization continued to complain of intractable femoral neuropathy 18 months afterwords. He failed multiple treatment modalities and continued to complain of severe neuropathic pains that markedly interfere with his daily activities. Two percutaneous leads were placed under real-time ultrasonography and the placement was confirmed with fluoroscopy. One lead was placed along the longitudinal axis of the nerve and the patient had good coverage over the anterior thigh but not below the knee. So another lead was placed horizontally across the femoral nerve in order to stimulate all the branches and the patient reported good coverage along the saphenous nerve distribution down to the foot.

RESULTS

The patient continues to be pain free 20 months after the implant.

CONCLUSION

Here we described a novel non-invasive percutaneous approach for femoral nerve stimulation with ultrasound guidance which allowed precise placement of the stimulating lead very close to the femoral nerve without the need for surgical exploration.

Neuroprosthetic effect of peroneal nerve stimulation in multiple sclerosis: a preliminary study

OBJECTIVE

To determine the neuroprosthetic effect of a peroneal nerve stimulator on tasks of functional ambulation in multiple sclerosis (MS).

DESIGN

A single point-in-time assessment of functional ambulation tasks under the conditions of no device and peroneal nerve stimulator.

SETTING

Outpatient academic medical center.

PARTICIPANTS

Participants (N=11) with diagnosis of MS (>6mo), dorsiflexion weakness, and prior usage of an ankle-foot orthosis.

INTERVENTION

Surface peroneal nerve stimulator for ambulation.

MAIN OUTCOME MEASURES

Timed 25-foot Walk portion of the MS Functional Composite; Floor, Carpet, Up and Go, Obstacle, and Stair components of the Modified Emory Functional Ambulation Profile.

RESULTS

Peroneal nerve stimulator-Stair performance was significantly enhanced (P=.05) versus no device, and statistical significance was approached for peroneal nerve stimulator-Obstacles (P=.09) versus no device. There were no significant differences between peroneal nerve stimulator and no device conditions in the remaining outcome measures.

CONCLUSIONS

The neuroprosthetic effect of the peroneal nerve stimulator is modest relative to no device in the performance of specific functional tasks of ambulation in MS gait. A longitudinal, controlled trial is needed to show effectiveness.

Optimizing electrode implantation in sacral nerve stimulation--an anatomical cadaver study controlled by a laparoscopic camera

BACKGROUND AND AIM

Sacral nerve stimulation is the therapy of choice in patients with neurogenic faecal and urine incontinence, constipation and some pelvic pain syndromes. The aim of this study is to determine the best insertion angles of the electrode under laparoscopic visualization of the sacral nerves.

MATERIALS AND METHODS

Five fresh cadaver pelvises were dissected through an anterior approach of the presacral space, exposing the ventral sacral roots. Needles and electrodes were inserted into the S3 foramen. Both right and left sides were used, with the traditional percutaneous procedure. The validation was done by a laparoscopic camera controlling the position of the needle and electrode on the nerve. The angles were assessed with a goniometer and were confirmed in two living patients.

RESULTS

The mean angle of insertion in the sagittal plane was 62.9+/-3 degrees (range, 59-70). In the axial plane, the mean angle for the left side was 91.7+/-13.5 degrees (range, 80-110) and 83.2+/-7.7 degrees for the right side (range, 75-95). These angles resulted in the optimal placement of the leads along the S3 sacral root, in all these cases.

CONCLUSIONS

This study allows direct visualization during the placement of the needle and electrode, thus permitting accurate calculations of the best angle of approach during the surgical procedure in sacral nerve stimulation. These objective findings attempt to standardize this technique, which is often performed with the aid of intra-operative fluoroscopy but still leaving a lot to chance. These insertion angles should help to find more consistent and reproducible results and thus improved outcome in patients.

Simulated neuroprosthesis state activation and hand-position control using myoelectric signals from wrist muscles

This paper reports on the initial phase of feasibility testing of a control strategy that uses myoelectric signals (MES) from wrist flexor and extensor muscles to control a hand-grasp neuroprosthesis for C7 tetraplegia. The control strategy was customized to the MES patterns produced during wrist flexion, extension, and relaxation for five able-bodied subjects and two individuals with C7 spinal cord injury. We evaluated the reliability with which the subjects could deliberately activate target neuroprosthesis states and control the degree of opening and closing of a computer-simulated hand using the myoelectric control strategy. Every subject was able to activate at least 99% of the target states for at least 1 continuous second, enough time to prove the activation was deliberate and to achieve significant hand opening or closing. Additionally, every subject was able to control the opening and closing of the simulated hand with enough proficiency to match greater than 87% of the target hand positions for at least 2 continuous seconds. Most of the inadvertent disturbances in simulated hand position were of a magnitude less than 10% of full range of motion for every subject. Future studies will incorporate the control strategy into an electrical stimulation system that opens and closes the hand of an individual with C7 tetraplegia.

Results of sacral neuromodulation therapy for urinary voiding dysfunction: outcomes of a prospective, worldwide clinical study

PURPOSE

This 5-year, prospective, multicenter trial evaluated the long-term safety and efficacy of sacral neuromodulation in patients with refractory urge incontinence, urgency frequency and retention.

MATERIALS AND METHODS

A total of 17 centers worldwide enrolled 163 patients (87% female). Following test stimulation 11 patients declined implantation and 152 underwent implantation using InterStim. Of those treated with implantation 96 (63.2%) had urge incontinence, 25 (16.4%) had urgency frequency and 31 (20.4%) had retention. Voiding diaries were collected annually for 5 years. Clinical success was defined as 50% or greater improvement from baseline in primary voiding diary variable(s).

RESULTS

Data for all implanted cases were reported. For patients with urge incontinence mean leaking episodes per day decreased from 9.6 +/- 6.0 to 3.9 +/- 4.0 at 5 years. For patients with urgency frequency mean voids per day decreased from 19.3 +/- 7.0 to 14.8 +/- 7.6, and mean volume voided per void increased from 92.3 +/- 52.8 to 165.2 +/- 147.7 ml. For patients with retention the mean volume per catheterization decreased from 379.9 +/- 183.8 to 109.2 +/- 184.3 ml, and the mean number of catheterizations decreased from 5.3 +/- 2.8 to 1.9 +/- 2.8. All changes were statistically significant (p <0.001). No life threatening or irreversible adverse events occurred. In 102 patients 279 device or therapy related adverse events were observed. At 5 years after implantation 68% of patients with urge incontinence, 56% with urgency frequency and 71% with retention had successful outcomes.

CONCLUSIONS

This long-term study demonstrates that InterStim therapy is safe and effective for restoring voiding in appropriately selected cases refractory to other forms of treatment.

[Spinal cord injury patient and Brindley neurostimulation]

Electrostimulation of anterior sacral nerve roots has been gradually developed since the 1970s and now represents a real alternative for the treatment of lower urinary tract dysfunction in neurological patients. In some cases, it can also allow improvement of erections and improvement of defecation. The success of the intervention largely depends on rigorous selection of the patients likely to benefit from this technique. In this article, the authors describe the technical principles of this procedure, the ideal patient profile of candidates for this procedure and the main results that can be achieved.

Blood flow changes in the trapezius muscle and overlying skin following transcutaneous electrical nerve stimulation

BACKGROUND AND PURPOSE

Various researchers have studied the effects of transcutaneous electrical nerve stimulation (TENS) on hemodynamics. The purpose of this study was to examine the effects of TENS on local blood flow in the trapezius muscle and overlying skin.

SUBJECTS

Thirty-three women who were healthy, aged 25 to 55 years, were randomly assigned to receive 1 of 3 different modes of TENS.

METHODS

Skin and muscle blood flow were monitored noninvasively using a new application of photoplethysmography for 15 minutes of TENS applied at high frequency (80 Hz) and sensory-level intensity and at low frequency (2 Hz) and motor-level intensity and for 15 minutes after stimulation. Subliminal 80-Hz TENS was used as a control. Blood flow was monitored simultaneously on stimulated and nonstimulated shoulders.

RESULTS

Blood flow in the trapezius muscle, but not skin blood flow, increased significantly with motor-level 2-Hz TENS, whereas no increase occurred with sensory-level 80-Hz TENS or subliminal 80-Hz TENS.

DISCUSSION AND CONCLUSION

Muscle contractions induced by motor-level 2-Hz TENS appear to be a prerequisite for increasing blood flow in the trapezius muscle. However, high stimulation intensity may prevent increased blood flow in the overlying skin.

Brachial plexus blocks: a review of approaches and techniques

PURPOSE

The purpose of this narrative review is to summarize the evidence derived from randomized controlled trials (RCTs) regarding established approaches and techniques for brachial plexus anesthesia.

SOURCE

Using the MEDLINE (January 1966 to November 2006) and EMBASE (January 1980 to November 2006) databases, key words "brachial plexus", "nerve blocks", "interscalene", "cervical paravertebral", "suprascapular", "supraclavicular", "infraclavicular", "axillary", "brachial canal" and "humeral canal" were searched for full text articles pertaining to the evaluation of recognized approaches and techniques for brachial plexus anesthesia. The search was limited to RCTs involving human subjects and published in the English language. Seventy-six RCTs were identified.

PRINCIPAL FINDINGS

Many of the published studies were underpowered and contained various methodological limitations. We found that, for shoulder and proximal humeral surgery, interscalene and cervical paravertebral approaches to the brachial plexus appear to provide equally effective surgical anesthesia. Intersternocleidomastoid supraclavicular blocks are not associated with improved postoperative analgesia despite eliciting more complete anesthesia of the brachial plexus. For surgery at or below the elbow, an infraclavicular block may result in decreased performance time and block-related pain while providing similar efficacy compared to (multiple-stimulation) axillary and brachial canal approaches. With respect to technique, it is unclear if nerve stimulation provides a more effective interscalene block than elicitation of paresthesiae. For supraclavicular blocks, nerve stimulation with a minimal threshold of 0.9 mA is recommended, whereas a double-stimulation technique is optimal for infraclavicular blocks. For the axillary approach, a triple-stimulation technique, involving injections of the musculocutaneous, median and radial nerves, is the most effective option.

CONCLUSIONS

Published reports of RCTs provide evidence to formulate limited recommendations regarding optimal approaches and techniques for brachial plexus anesthesia. Further well-designed and meticulously executed RCTs are warranted, particularly in light of new techniques involving ultrasound or combining neurostimulation and echoguidance.

Effects of noninvasive transcutaneous electrical stimulation via concentric ring electrodes on pilocarpine-induced status epilepticus in rats

PURPOSE

The aim of this pilot study was to investigate the antiepileptic effects of a novel noninvasive stimulation technique, transcutaneous electrical stimulation (TcES) via scalp concentric ring electrodes, on pilocarpine-induced status epilepticus (SE) in rats.

METHODS

Five minutes after the onset of SE, TcES was administered to the experimental rat via bipolar concentric ring electrode at the CZ location. Symmetrical, biphasic, charge-balanced, constant current, isolated pulses were applied via a custom-made stimulator. TcES parameters ranged from 200-750 Hz, 200 or 300 mus pulse duration, and 50 or 60 mA, applied for 1 min, started with the least intense parameter set and progressively increased.

RESULTS

TcES attenuated electrographic seizure activity and halted the progression of behavioral seizures. Interruption of seizure activity outlasted the period of stimulation and appeared to be long-lasting. TcES treatment significantly extended the life and enhanced the survival of rats after SE.

CONCLUSIONS

Noninvasive TcES, applied 5 min after SE onset via novel concentric ring electrodes on the scalp, reduced, or abolished electrographic and behavioral seizure activity in pilocarpine-induced SE in rats. These findings suggest that TcES may have a role in the treatment of SE.

Ultrasound Guidance for Lateral Midfemoral Sciatic Nerve Block: A Prospective, Comparative, Randomized Study

Block of the sciatic nerve at the midfemoral level is usually performed using nerve stimulation techniques. We investigated the efficacy of ultrasound, combined with nerve stimulation, to locate and block the sciatic nerve at the lateral midfemoral level compared to nerve stimulation alone. Sixty-one patients scheduled for foot and ankle surgery were enrolled in this prospective, randomized study. Thirty patients underwent a lateral block of the sciatic nerve at the midfemoral level guided by ultrasound (group US) and 31 patients received the block without ultrasound (group ES). Once an adequate motor response was obtained using nerve stimulation, 35 mL of ropivacaine 0.5% was administered. The main end-points of the study were: number of attempts to obtain an adequate motor response, success rate of nerve location at the first attempt, quality and duration of both sensory and motor blocks, and anesthetic distribution. The success of sciatic nerve location at the first attempt was significantly more frequent in the US group than in the ES group (76.6% versus 41.9%; P < 0.001). The quality of the sensory block and the tolerance to the pneumatic tourniquet were also significantly better in the US group (P < 0.01). We conclude that ultrasound combined with nerve stimulation improved the quality of the sensory block and the tolerance to the pneumatic tourniquet, reducing the number of attempts to perform sciatic nerve block at the midfemoral level.

Neurostimulation in Ultrasound-Guided Infraclavicular Block: A Prospective Randomized Trial

Ultrasound guidance (USG) for infraclavicular blocks provides real time visualization of the advancing needle and local anesthetic distribution. Whether visualization of local anesthetic spread can supplant neurostimulation as the end point for local anesthetic injection during USG block has never been formally evaluated. Therefore, for this prospective randomized study, we recruited 72 patients scheduled for hand or forearm surgery and compared the speed of execution and quality of USG infraclavicular block with either USG alone (Group U) or USG combined with neurostimulation (Group S). In Group U, local anesthetic was deposited in a U-shaped distribution posterior and to each side of the axillary artery using as few injections as possible (1, 2, and 3 injections in 29, 6, and 3 patients, respectively). In Group S, a single injection was made after obtaining a distal motor response with a stimulating current between 0.3 and 0.6 mA. The anesthetic solution consisted of 0.5 mL/kg of lidocaine 1.5%, bupivacaine 0.125%, and epinephrine 1:200 000 (final concentrations). Procedure times were significantly shorter in Group U compared with Group S (3.1 +/- 1.6 min and 5.2 +/- 4.7 min, respectively; P = 0.006). In Group S, anesthetic spread was mainly anterior to the axillary artery in 37% of patients and mainly posterior in 63% of patients. Thirty minutes after the injection, 86% of patients in Group U had complete sensory block in the musculocutaneous, median, radial, and ulnar nerve territories compared with 57% in Group S (P = 0.007). Patients blocked in Group U with a single injection had the same rate of complete block (86%) as those blocked with more than one injection (86%). Block supplementation rates were 8% in Group U versus 26% in Group S (P = 0.049). Block failure occurred in one patient in Group S because of an inability to obtain a distal stimulation after 20 min. We conclude that USG infraclavicular block is more rapidly performed and yields a higher success rate when visualization of local anesthetic spread is used as the end point for injection. Posterolateral spread of local anesthetic around the axillary artery predicts successful block, circumventing the need for direct nerve visualization.

Frequency rhythmic electrical modulation system (FREMS) on H-reflex amplitudes in healthy subjects

AIM

Changes in the amplitude of Hoffmann reflex (H-reflex) may reflect variations in the characteristics of the largely monosynaptic circuitry that is explored and are a possible target for diagnostic and physical therapeutic intervention. However, previous attempts to induce predictable changes in the H-reflex amplitude by transcutaneous electrical nervous stimulation (TENS) have generally failed. Previous workers applied fixed frequency in the low- (2-5 Hz) or in the high- (100 Hz) field, but they did not attempt to vary frequency and/or impulse duration in time.

METHODS

We evaluated the effect of a new type of painless electric stimulation, i.e. frequency rhythmic electrical modulation system (FREMS). FREMS is characterized by the use of transcutaneous electric pulses with sequentially modulated frequency (f: 1-39 Hz) and width (w: 10-40 micro s) at constant, perceptive threshold voltage (approximately 150 V). FREMS was applied at the abductor hallucis muscle (AHM), as conditioning stimulus of the H-reflex which was recorded ipsilaterally at the soleus muscle, according to the classic method, in 10 normal volunteers (age range 21-40 years).

RESULTS

H-reflex amplitude was substantially decreased (-50%) during FREMS and H-reflex amplitude variations were influenced by w/f variation in time during FREMS subphase C in a predictable way (r(2)=0.43; P<0.001). Our results suggest an effective ability of FREMS to modulate H reflex amplitude.

CONCLUSIONS

The ability to achieve large and predictable changes of the H-reflex amplitude simply by modulating both frequency and duration of a conditioning painless electrical stimulation offers new possibilities for the treatment of diseases characterized by motoneuron excitability abnormalities.

Défaut de circuit électrique et neurostimulation: cas cliniques et procédure de prévention

Functionality of the nerve stimulator and integrity of the electrical circuit should be verified and confirmed before performing peripheral nerve blockade. The clinical cases reported here demonstrate that electrical disconnection or malfunction during nerve localization can unpredictably occur and a checklist is described to prevent the unknown electrical circuit failure.

Use of tens in pain management: part two--how to use tens

Transcutaneous electrical nerve stimulation is widely used in pain management but its effectiveness depends on the stimulation being targeted appropriately. This article, the second in a two-part series, outlines how to set up and use a TENS machine to achieve the most effective results.

[Use of rechargeable stimulators in 2 cases of cauda equina syndrome]

The first of the 2 cases of cauda equina syndrome we report occurred following phenolization of sacral roots after a series of operations for Hirsprung disease. The second occurred after trauma from a bullet that hit the spine. Fecal and urinary incontinence and neuropathic pain in the lower extremities were present in both cases. After various treatments failed, both patients were given dual spinal stimulation for integrated treatment of both incontinence and neuropathic pain. We applied a novel approach, connecting both stimulators to a single rechargeable generator, reducing medium- and long-term costs. Fewer generator replacements (every 2-3 years with the standard approach) and fewer generator implantations (2 each time with the usual system) are required when rechargeable generators are used. Patient quality of life is thus improved. The overall cost of the implants is reduced from their second year of use.

[Transcutaneous electric stimulation of nerves use in comprehensive treatment of patients with mandibular fractures]

60 patients with mandibular fractures were checked up and in whom clinically and with the help of neurophysiological methods some sensori-paresthetic disorders were diagnosed. Pain syndrome expression in cases of fractures and contraindication to analgesics use in a number of patients dictate the necessity to search new treatment methods of this category of patients. The use of transcutaneous electric stimulation of nerves allowing in short periods of time to stop pain syndrome and reduce the number of complications in cases of mandibular fractures was substantiated.

Vagus nerve stimulation in chronic treatment-resistant depression: preliminary findings of an open-label study

We evaluated the efficacy and safety of vagus nerve stimulation therapy in the treatment of 11 patients with chronic treatment-resistant depression. Mood was evaluated at frequent intervals over the year following implantation. All measures of depression, including the Hamilton Rating Scale for Depression reduced significantly. The response and remission rates were 55% and 27% respectively at 1 year. Side-effects were common, and some were severe.

[Equipment for spinal cord stimulation]

Spinal cord stimulation has gained widespread popularity for the treatment of pain. This literature discribed our equipments, methods, patient selection, and operative procedures for spinal cord stimulation.

Intraoperative Motor Evoked Potential Monitoring: Overview and Update

Amidst controversy about methodology and safety, intraoperative neurophysiology has entered a new era of increasingly routine transcranial and direct electrical brain stimulation for motor evoked potential (MEP) monitoring. Based on literature review and illustrative clinical experience, this tutorial aims to present a balanced overview for experienced practitioners, surgeons and anesthesiologists as well as those new to the field. It details the physiologic basis, indications and methodology of current MEP monitoring techniques, evaluates their safety, explores interpretive controversies and outlines some applications and results, including aortic aneurysm, intramedullary spinal cord tumor, spinal deformity, posterior fossa tumor, intracranial aneurysm and peri-rolandic brain surgeries. The many advances in motor system assessment achieved in the last two decades undoubtedly improve monitoring efficacy without unduly compromising safety. Future studies and experience will likely clarify existing controversies and bring further advances.

[Clinical evaluation of electronic dental analgesia during ultrasonic scaling]

OBJECTIVE

To evaluate the effect of electronic dental analgesia (EDA) device--Team Up Duo during ultrasonic scaling.

METHODS

The clinical trial was conducted as a randomized double-blind split-mouth design. Eighty-one patients requiring ultrasonic scaling were selected as subjects. Patients received treatment using the EDA device either in an active or an inactive state in paired quadrants. The patients scored their pain/discomfort levels with visual analog scale (VAS) after each procedure and filled a questionnaire.

RESULTS

In questionnaire, 79.0% patients felt EDA could relieve pain/discomfort during ultrasonic scaling. But the double-blind test showed that Team Up Duo was effective in 46.9% patients overall. The effective rate was 55.1% and 34.4% in groups with or without attachment loss, respectively. In CP group, the success rate of EDA was not statistically significantly different between the groups according to sex, age or site.

CONCLUSIONS

When using Team Up Duo during ultrasonic scaling, most patients subjectively believed that it was effective for controlling pain. In fact, this EDA device was effective in partial patients.

Evaluation and management of malfunctioning sacral neuromodulator

OBJECTIVES

To describe a strategy for revising the malfunctioning InterStim device and to provide an algorithm for evaluation and management.

METHODS

We retrospectively reviewed 82 patients who had undergone InterStim placement. Ten patients (eight women and two men) experienced complications and subsequently underwent revision of their device between October 2001 and October 2003. Five patients had originally received a permanent implant after a successful percutaneous test stimulation trial, and five had undergone a test stimulation using the tined lead. Indications for revision included gradual onset of recurrent voiding dysfunction (n = 2), lead migration (n = 5), generator malfunction (n = 1), generator site pain and infection (n = 1), and genital/rectal pain with stimulation (sensory discomfort; n = 1).

RESULTS

Of the 10 patients who underwent revision, 7 experienced complete resolution of their problem. Eight patients had lead site changes and two had generator replacements. No intraoperative or postoperative complications occurred in the revision cases.

CONCLUSIONS

In our experience, 70% of patients who undergo revision of the malfunctioning InterStim can expect success. In this study, no difference in success appeared to be related to the original cause of malfunction. In the management of malfunctioning sacral neuromodulators, we recommend an attempt at revision before permanent explantation.

Analgesic and disease modifying effects of interferential current in psoriatic arthritis

Interferential current (IFC) was suggested to improve the skin manifestations of psoriasis vulgaris, possibly by enhancing the intracellular concentration of cyclic AMP. We assessed the efficacy of IFC on psoriatic arthritis (PsA). Nine consecutive patients were analyzed at baseline and after 16 weeks of IFC therapy. Bipolar IFC was applied twice daily to hands, feet plus all affected joints. IFC improved SF-36 assessed body pain, but not other SF-36 subscales. Morning stiffness, tender joint counts, and physician assessed disease activity improved. In contrast, visual analogue scale assessed pain, CRP and ESR measurements were unchanged. MRI of the most affected hand or foot documented a tendency towards worsened tendinitis, soft tissue swelling, and new joint space narrowing and erosions. Bone scintigraphy showed a trend towards deterioration. New joints became inflamed within treated sites. Thus IFC has analgesic effects in PsA, but does not have a satisfactory disease modifying effect.

Electrical treatment of reduced consciousness: experience with coma and Alzheimer's disease

The right median nerve can be stimulated electrically to help arouse the central nervous system for persons with reduced levels of consciousness. The mechanisms of central action include increased cerebral blood flow and raised levels of dopamine. There is 11 years of experience in the USA of using nerve stimulation for acute coma after traumatic brain injury. There is a much longer period of experience by neurosurgeons in Japan with implanted electrodes on the cervical spinal cord for persons in the persistent vegetative state (PVS). But the use of right median nerve electrical stimulation (RMNS) for patients in the subacute and chronic phases of coma is relatively new. Surface electrical stimulation to treat anoxic brain injury as well as traumatic brain injury is evolving. Novel applications of electrical stimulation in Amsterdam have produced cognitive behavioural effects in persons with early and mid-stage Alzheimer's disease employing transcutaneous electrical nerve stimulation (TENS). Improvements in short-term memory and speech fluency have also been noted. Regardless of the aetiology of the coma or reduced level of awareness, electrical stimulation may serve as a catalyst to enhance central nervous system functions. It remains for the standard treatments and modalities to retrain the injured brain emerging from reduced levels of consciousness.

[A method for prevention of exposure of acupuncture points to undesirable effects]

Analysis of currently used medical electrostimulation equipment shows that under certain conditions (determined by current characteristics and electrode size) the skin is exposed to considerably high electric current. If an electrode is applied to skin region containing acupuncture points, unintentional and, therefore, uncontrollable exposure to electric current can have a detrimental effect on the health and the functional state of human body. In this work, an algorithm for preventing unintentional exposure of acupuncture points to electrostimulation is considered. The algorithm can be implemented using special electrodes consisting of insulated segments. Electric commutation of segments makes it possible to change automatically the working configuration of electrodes.

Changes in regional cerebral blood flow by therapeutic vagus nerve stimulation in depression: an exploratory approach

Abnormalities in regional cerebral blood flow (rCBF) have been reported to characterize depressive episodes; they are at least partly reversed by antidepressant treatment. Treatment-specific as well as response-related changes in rCBF have been reported. We explored the changes in rCBF induced by vagus nerve stimulation (VNS), a recently proposed antidepressant strategy, by application of single photon emission-computed tomography with (99m)Tc-hexamethyl-propylene amine oxime in otherwise treatment-refractory patients. Both region-of-interest (ROI) and statistical parametric mapping (SPM) analytic approaches were used. Decreases of rCBF in the amygdala, left hippocampus, left subgenual cingulate cortex, left and right ventral anterior cingulum, right thalamus and brain stem were observed; the only increase of rCBF was found by SPM analysis in the middle frontal gyrus. This pattern shares features with changes of rCBF previously associated with the administration of selective serotonin reuptake inhibitors. Similarities to other brain-stimulation strategies in antidepressant treatment were less pronounced.

Spinal cord stimulation for axial low back pain: a prospective, controlled trial comparing dual with single percutaneous electrodes

STUDY DESIGN

A prospective, controlled, clinical trial comparing single and dual percutaneous electrodes in the treatment of axial low back pain from failed back surgery syndrome.

OBJECTIVES

To clarify technical requirements and test the hypothesis that placing two linear arrays in parallel, thereby doubling the number of contacts, improves outcome.

SUMMARY OF BACKGROUND DATA

Technical improvements have enhanced outcomes of spinal cord stimulation for chronic axial low back pain. Dual, parallel electrodes reportedly improve these outcomes.

METHODS

Acting as their own controls, 20 patients who passed screening with single, 4-contact electrodes received permanent dual, 4-contact electrodes with 7- or 10-mm intercontact distances at the same vertebral level(s). We quantified and compared the technical and clinical results of the single and dual electrodes, adjusting stimulation parameters to specific psychophysical thresholds.

RESULTS

Single electrodes provided significant (P < 0.01) advantages in patient- and computer-calculated ratings of pain coverage by paresthesias and in the scaled amplitude necessary to cover the low back, compared with dual 7-mm electrodes. Slight advantages without statistical significance were observed for the single over the dual 10-mm electrodes. Amplitude requirements were significantly lower for the single electrode than for either dual electrode. At long-term follow-up, 53% of patients met the criteria for clinical success.

CONCLUSIONS

While we observed disadvantages for dual electrodes in treating axial low back pain, we achieved technical success with single or dual electrodes in most patients and maintained this success clinically with dual electrodes in 53%.

Modular transcutaneous functional electrical stimulation system

A new multipurpose programmable transcutaneous electric stimulator, Compex Motion, was developed to allow users to design various custom-made neuroprostheses, neurological assessment devices, muscle exercise systems, and experimental setups for physiological studies. Compex Motion can generate any arbitrary stimulation sequence, which can be controlled or regulated in real-time using any external sensor or laboratory equipment. Compex Motion originated from the existing Compex 2 electric stimulator, manufactured by a Swiss based company, Compex SA. The Compex Motion stimulator represents a further evolution and expansion of the ETHZ-ParaCare functional electrical stimulation system. This stimulator provides all the advanced functional electrical stimulation (FES) application and control features and can be easily incorporated into any standard rehabilitation program. Compex Motion has successfully been applied as a neuroprosthesis for walking, reaching and grasping in more than 100 stroke and spinal cord injured patients. This system has also been used to strengthen muscles and to investigate muscle properties in able-bodied subjects. Compex Motion is a multipurpose FES system specially designed to promote sharing and exchanging of stimulation protocols, sensors, and user interfaces. To the best of our knowledge an FES system that has similar capabilities does not exist yet.

Locating the target nerve and injectate spread in rabbit sciatic nerve block

BACKGROUND AND OBJECTIVES

The purpose of this study is to determine how close the needle tip is placed to the target nerve using a nerve stimulator and to determine how far the injectate spreads in percutaneous nerve blocks.

METHODS

Twenty-four sciatic nerves of New Zealand white rabbits were located with a 2-dimensional needle manipulator and a nerve stimulator (pulse width: 100 micros for group I, 250 micros for group II). The stimulation current required to elicit a motor response for each insertion depth of the needle and the nerve-needle distance at which the required current reached the minimum were measured. Another 10 sciatic nerves were located manually using a nerve stimulator and neurolyzed with a mixed solution of 5% phenol and Indian ink (100 microL).

RESULTS

The nerve-needle distance was in the range of -1.2 mm to +2.8 mm in group I (1.1 +/- 0.9 mm [mean +/- standard error] in absolute value) and -0.2 mm to +4.8 mm (2.2 +/- 1.7 mm [mean +/- standard error] in absolute value) in group II (positive values signify the center of the beveled surface is past the nerve), when the stimulation current reached the minimum (average minimum current: 0.47 mA in group I, 0.37 mA in group II). Indian ink spread over a significant distance (25.4 +/- 0.5 mm [mean +/- standard error]; range, 19-31 mm) longitudinally within the perineural tissue, and axonal degeneration was observed linearly at the peripheral portion of the nerve fascicle in a similar pattern as Indian ink spread.

CONCLUSIONS

The target nerve was located within 5 mm from the needle with less than 0.5-mA stimulation current. The injectate spread to more than 20 mm on average even when a small volume (100 microL) of the injectate was injected in rabbit sciatic nerves.

Percutaneous electrode guidance using the insulated needle for prelocation of peripheral nerves during axillary plexus blocks

BACKGROUND AND OBJECTIVES

Short reports have noted that percutaneous prelocation is helpful in determining the anatomic course of a peripheral nerve, and, thereby, may serve as a guide for block needle insertion. We prospectively studied percutaneous electrode guidance to assist axillary brachial plexus blocks.

METHODS

In 131 consecutive patients, the tip of an insulated needle emitting 5 mA was placed on the skin above and below the axillary artery to obtain a hand motor response characteristic of the median, ulnar, and radial nerves in succession. The current was reduced until all movement had ceased. The needle was then inserted toward the nerve to be blocked, decreasing the intensity from 2 mA to 0.5 mA, so that the same selected motor response was still obtained. The length of the needle inserted was noted, and 1.5% lidocaine was injected. Pain verbal analogic score (VAS) values were noted during both procedures. Complete sensory blockade was evaluated at 30 min.

RESULTS

Rates of successful percutaneous electrode guidance were 94.6% for the median nerve, 89.4% for the radial nerve, 88.5% for the ulnar nerve, and 85.5% for all 3 nerves together. A significant correlation was found between the lowest percutaneous current applied and the depth of the nerve stimulated at 0.5 mA. Pain VAS values were significantly lower during percutaneous stimulation than during needle insertion (P <.05). Sensory block for all 3 nerves was noted in 92% of patients.

CONCLUSIONS

Percutaneous electrode guidance using the insulated needle enabled clinicians to locate the terminal branches of the plexus in the axilla and appreciate their depth. This method could, therefore, minimize patient discomfort and perhaps the risk of nerve trauma.

Stimulation artifact in surface EMG signal: effect of the stimulation waveform, detection system, and current amplitude using hybrid stimulation technique

The purpose of this study was to investigate the amplitude properties of the artifact generated on the recorded surface electromyography (EMG) signals during transcutaneous electrical muscle stimulation. The factors which were investigated are the shape of the stimulation waveform, the distance of the stimulating electrode from the recording system, the interelectrode distance of the detection system, the spatial filter used for signal detection, and the stimulation current amplitude. Surface EMG signals were recorded during electrical stimulation of the biceps brachii motor point with a linear adhesive array of eight electrodes. Electrical stimulation was applied with seven stimulation waveforms (mono- and biphasic triangular, sinusoidal, and rectangular), generated by a specifically designed neuromuscular stimulator with hybrid output stage. The stimulation peak current was linearly increased from 0 mA to the maximum tolerated by the subject. The detection systems investigated were single and double differential with interelectrode distances multiple of 5 mm. Two trials for each contraction were performed on three different days. The average rectified artifact values (both absolute and normalized with respect to the corresponding M-wave values) were computed to investigate the artifact amplitude properties. Results indicated that, while the artifact average rectified value, normalized with respect to the M-wave amplitude, depended on the distance of the detecting electrodes from the stimulation point, it did not depend on the stimulation waveform, on the current intensity, on the interelectrode distance, and on the spatial filter. It was concluded that, using hybrid stimulation techniques, the selection of particular stimulation waveforms, interelectrode distances, or spatial filters has a minor effect on the reduction of the artifact when recording M-waves.

Physiologic responses to electrically assisted and frame-supported standing in persons with paraplegia

BACKGROUND

Systems of functional electrical stimulation (FES) have been demonstrated to enable some persons with paraplegia to stand and ambulate limited distances. However, the energy costs and acute physiologic responses associated with FES standing activities have not been well investigated.

OBJECTIVE

To compare the physiologic responses of persons with paraplegia to active FES-assisted standing (AS) and frame-supported passive standing (PS).

METHODS

Fifteen persons with paraplegia (T6-T11) previously habituated to FES ambulation, completed physiologic testing of PS and AS. The AS assessments were performed using a commercial FES system (Parastep-1; Altimed, Fresno, Calif); the PS tests used a commercial standing frame (Easy Stand 5000; Altimed, Fresno, Calif). Participants also performed a peak arm-cranking exercise (ACE) test using a progressive graded protocol in 3-minute stages and 10-watt power output increments to exhaustion. During all assessments, metabolic activity and heart rate (HR) were measured via open-circuit spirometry and 12-lead electrocardiography, respectively. Absolute physiologic responses to PS and AS were averaged over 1-minute periods at 5-minute intervals (5, 10, 15, 20, 25, and 30 minutes) and adjusted relative to peak values displayed during ACE to determine percentage of peak (%pk) values. Absolute and relative responses were compared between test conditions (AS and PS) and across time using two-way analysis of variance.

RESULTS

The AS produced significantly greater values of VO2 (43%pk) than did PS (20%pk). The mean HR responses to PS (100-102 beats per minute [bpm] throughout) were significantly lower than during AS, which ranged from 108 bpm at 5 minutes to 132 bpm at test termination.

CONCLUSION

Standing with FES requires significantly more energy than does AS and may provide a cardiorespiratory stress sufficient to meet minimal requirements for exercise conditioning.

Functional electrical stimulation for augmented walking in adolescents with incomplete spinal cord injury

BACKGROUND/OBJECTIVE

This study evaluated the effects of functional electrical stimulation (FES) applied to the muscles acting on the pelvis, hip, and knee on muscle strength, energy cost of walking, maximum walking distance and speed, step length and cadence, and joint kinematics during gait in 3 ambulatory adolescents with incomplete spinal cord injury (SCI).

METHODS

Percutaneous FES was used to strengthen weakened muscles and to augment walking. After training, participants walked as desired at home with FES for 1 year. Data were collected at baseline (preintervention), and with FES on and FES off immediately following the training period and with FES on and FES off at 3, 6, and 12 months posttraining.

RESULTS

Voluntary strength improved in 12 out of 13 stimulated muscles. Decreased energy cost, increased maximum walking distance and speed, increased step length, and improved joint kinematics during gait were demonstrated with FES on and FES off.

DISCUSSION

FES was able to achieve selective stimulation of key weakened muscles for augmented walking. The data suggest that FES had both direct and carryover effects.

Impact of low frequency transcutaneous electrical nerve stimulation on symptomatic diabetic neuropathy using the new Salutaris device

In a double blind, randomised study, 19 patients suffering from mild-to-moderate symptomatic diabetic neuropathy (Total Symptom Score, NTSS 4-16) received either treatment with the new transcutaneous electrical nerve stimulation (TENS) device "Salutaris" (verum group) or a placebo treatment with an identical but electrically inactive device (placebo group). Stimulation pads were placed at the anatomical localisation of the peroneal nerve and stimulation was performed using a low frequency mode. At baseline (V1), after 6 (V2), and 12 (V3) wk of treatment, the patients' symptoms were registered using the new total symptom score (NTSS-6) and a visual analogue scale (VAS). In addition, sensory nerve thresholds (temperature, vibration, pain) and microvascular function were measured at the lower limb at baseline and after 12 wk of treatment. Active TENS-treatment resulted in a significant improvement in NTSS-6 score after 6 wk (-42%) and after 12 wk (-32%) of treatment (baseline: 10.0+/-3.3, 6 wk: 5.8+/-5.0, p<0.05; 12 wk: 6.8+/-3.9, p=0.05; placebo group: baseline: 7.6+/-3.1; 6 wk: 8.1+/-5.1, n.s.; 12 wk: 6.5+/-6.1, n.s.). Subanalysis of the different qualities of the NTSS-score revealed an improvement in numbness (2.2+/-1.0 to 1.6+/-1.3; p<0.03); lancinating pain (1.6+/-1.1 to 0.6+/-0.9; p<0.02) and allodynia (1.4+/-1.6 to 0.5+/-1.0; p<0.05). Also, a significant improvement in the VAS rating was found after 6 wk of TENS therapy (19.8+/-5.0 to 14.4+/-9.6; p<0.05), while no change was observed in the placebo arm. In conclusion, our study indicates that the new TENS device "Salutaris" is a convenient, non-pharmacological option for primary or adjuvant treatment of painful diabetic neuropathy.

Electrical Nerve Localization

Background

Recommendations regarding the technical aspects of nerve stimulator-assisted nerve localization are conflicting. The objectives of this study were to determine whether the placement of the cutaneous electrode affects nerve stimulation and to determine the duration and intensity of an electrical stimulus that allows nerve stimulation with minimal discomfort.

Methods

Ten healthy volunteers underwent an interscalene and a femoral nerve block. After obtaining a clearly visible motor response of the biceps (interscalene) and quadriceps (femoral) muscles at the minimal current (0.1 ms, 2 Hz), the position of the cutaneous electrode was varied. Next, the duration of the stimulating current was set at 0.05, 0.1, 0.3, 0.5, or 1.0 ms, in random order. Intensity of the motor response and discomfort on stimulation were recorded.

Results

The minimal current at which a visible motor response was obtained was 0.32 +/- 0.1 mA (0.23-0.38 mA) for the inter-scalene block and 0.29 +/- 0.1 mA (0.15-0.4 mA) for the femoral block. Changing the position of the return electrodes did not result in any change in the grade of the motor response or in the current required to maintain it. Currents of longer duration caused discomfort and more forceful contraction at a lower current intensity as compared with currents of shorter duration (P &lt; 0.01). When the current was adjusted to maintain the same visible motor response, there was no significant discomfort among studied current durations.

Conclusion

Site of placement of the cutaneous electrode is not important when constant current nerve stimulators are used during nerve localization in regional anesthesia. There is an inverse relation between the current required to obtain a visible motor response and current duration. Selecting a current duration between 0.05 and 1.0 ms to specifically stimulate sensory or motor components of a mixed nerve does not seem to be important in clinical practice.

Development of a circuit for functional electrical stimulation

This paper examines the various design of a multiple-purpose portable functional electrical stimulator which is used in surface stimulation of paralyzed muscle of patients with stroke and results in limb activation. The functionality, circuit performance and reliability of the circuits will be examined. Analysis, design, and experimental results are presented.

[Transcutaneous electrical nerve stimulation in treatment of rheumatoid arthritis patients]

The aim of the study was pain management in rheumatoid arthritis patients (n=10) by applying the method of transcutaneous electrical nerve stimulation. The 10-point visual analogue scale was used before stimulation and following it. The total number of pain measurement tests in the joints was 180. The estimated average pain before stimulation was evaluated by 6.56+/-0.17 points and following it by 5.88+/-0.18 points. The average pain decrease after stimulation (Pt<0.05) was 10.4 %, compared with the control level.